Discuss The Viv Lab Rigid Arm

I understand the mathematic fundamentals behind digital audio, for example (Fourier, Shannon/Nyquist), yet intuitively it still seems impossible to me.

Like any technology digital had an uphill path to follow. For example jitter was a thing known to cause problems... I have a transport from the early 1990s  (Teac) that was highly respected at the time. But over time its pretty obvious its gone out of date. People update them with better clocks. The newer clock boards you can get on eBay for $20.00 have two orders of magnitude greater frequency stability; after installation this aged transport sounds a lot better...

Some people are dumbfounded by how 'dragging a rock thru a groove' could possibly work; not really realizing that their old saw isn't describing what's happening, because:

There is no substitute for experience.

This is correct.

Its also helpful to know what people have experienced prior to making blanket statements about them. Is mechanical design experience helpful? Is the experience of learning from your mistakes helpful? Is the experience of connecting what measurements we can make with what we hear helpful?

atmasphere

... Is the experience of connecting what measurements we can make with what we hear helpful?

Exactly, and that has been my point in this thread. To make real progress, we need to correlate measurements with what we hear. I think that should be true in all aspects of audio equipment design - not just pickup arms. Obviously others are willing to dispense with the listening part.

Exactly, and that has been my point in this thread. To make real progress, we need to correlate measurements with what we hear.

@cleeds Its been my experience that's what you do to sort out what's going on.

That is what led me to increasing rigidity in the plinth of our turntable; increasing coupling between arm and platter surface and overall making it dead as possible- damped platter, damped plinth. As I did these things the impervious nature of the system began to emerge; when I started the system was sensitive to volume pressures of 90dB; after I was done even at 105dB it was measurably and audibly superior. 

My technique was to place the stylus on the platter pad and measure the phono preamp output while playing a 100Hz tone thru the line stage of the preamp, amps and speakers. 'Success' was in reducing the output. I found that the better the coupling, the more dead the system, the lower the output at any frequency accompanied by a perceived improvement in bass, mids and highs- the system sounded less congested.

Damping the platter was easy but the plinth got tricky since it had to be machined out of solid aluminum.

I've been trying to correlate amplifier distortion vs how the amplifier 'sounds' for a very long time. My experience with that is both the measurement guys and those that prefer to only trust their ears hate what I've been finding. I think this is because the work messes with their world view. Its not surprising to find some pushback on this thread on the same account.

Lew and Dave: The Viv armtube can slide back and forth in the direction of its length through the housing by about 1mm. It can rotate around the axis of the tube a few degrees and it can be lifted a couple of mm to the top of the housing, tho here it takes some lifting to oppose the magnetic force of the fluid--not likely to happen during play.

@maxson 

Thanks for confirming.  I suspect it is this additional ability for movement that plays a big part in the arms response to and recovery from movements that cause mistracking. 

dave